树脂粘结剂对放射线损伤牙釉质粘结效果的实验研究

A comparison of the bonding strength between self-etching and total-etching systems to irradiated enamel

目的:评价全酸蚀粘结系统(PB)和自酸蚀粘结系统(GB)对放射线损伤牙釉质的粘结效果。方法:将20个新鲜完整的离体第三磨牙随机分成4组(n=5)。P1、G1为实验组,分次完成总量为60 Gy的60Co照射;PR、GR为对照组,不作任何处理。照射完成后,PR、P1组用PB粘结;GR、G1组用GB粘结,然后用扫描电镜及万能材料测试机分别对其粘结界面和微拉伸粘结强度(MBS)进行分析和检测。结果:牙釉质MBS P1组低于PR组(P=0.00);G1组与GR组比较P>0.05。两种粘结系统间比较,牙釉质MBS PR组高于GR组(P=0.00);P1与G1组比较,P>0.05。扫描电镜下,4组样本的拉伸断裂模式多为粘结界面和混合断裂模式,各组间无显著差异(P>0.05),PR组牙釉质与粘结剂形成的混合层厚度均匀,而P1组混合层厚度不均匀,树脂突结构紊乱。G1组的混合层较GR组薄,仅少量树脂突形成。结论:PB和GB对放射线损伤牙釉质的MBS均降低,二者效果无明显差别。

AIM： To evaluate the bonding effects of total-etch adhesive system （ Prime＆Bond NT, PB） and all in one self-etching adhesive system（G-Bond, GB） to irradiated enamel.METHODS：20 freshly extracted caries-free third molars were randomly divided into 4 groups （ n=5）. The experimental groups were irradiated with 60Co of 60Gy, and were then bonded with PB（P1 group） and GB（G1 group） respectively.Samples in control groups received no irradiation and were bonded with PB （PR group） and GB （GR group） respectively.The microtensile bond strength（MBS） was measured on a Micro Tester , the bond interface was observed by SEM. RESULTS： The MBS of P1 group was weaker than PRgroup （P=0. 00）, and that of G1 was not statistically different from that of GR（P〉0.05）.The MBS was not statistically different between PR and GR（ P〉0.05）.No significant structural differ-ence was observed among the 4 groups under SEM. CONCLUSION：Irradiation decreases the MBS of PB and GB ad-hesives to enamel. Total-and self-etching bonding systems have similar effect for bongind irradiated enamel.